From a normal stand point, performance anxiety could have been a factor because it may have been he´s first time on camera and even profissional performers sometimes have trouble. From a critical stand point , it was a video not live performance, so he should have done some "prep" before filming and the constant talking wasn´t ,IMO, good. We wanted the hear her not the guy every 10 seconds.
In summary, it was a "OK" video for a first video, Kylie was stunning and the filming was good.